In this thread, I am going to describe how I separated the rear turn signal from the stop signal. I believe it should work for 2002-2005 hatchbacks models. I want to give a credit to Hunt-r
from the Ford Focus Club RU
who provided me with the detailed information on the GEM output. In no way can I be held liable for any damage you may cause to your car's electronics by attempting the following procedure.
Please try to figure out where you want to position your new reverse lights as the old ones will become blinkers.
Before you start working on this project, obtain the following tools:
The second picture depicts a 6-12 V curcuit tester. The wire in the first picture should be about 16 GA. The blue 3-way connectors should read 18-14 GA. Your local Wal-Mart would have all these tools very cheap.
Empty your glovebox and move it to outside. Behind the glovebox on the right, you should see the following:
The whole thing is called a GENERIC ELECTRONIC MODULE (GEM). Those five harnesses that are secured to the GEM by the yellow locks are the outputs. Disconnect the gray harness (#1), the green harness (#2), and the blue harness (#3).
Make sure you provide enough light to differentiate between the coloured wires. Remove the black insulation as to have free access to the coloured wires in each harness.
- In gray harness (#1), you have to find the blue wire. Cut it approximately 3 cm downward from the harness. It used to be your left rear turn/stop signal.
- In green harness (#2), find the blue-red wire, and cut it in the same way as you did in step a. It used to be the right rear turn/stop signal.
- In blue harness (#3), find the BLUE-white wire (blue part is wider than white), but don't cut it. Instead, connect the blue wire from step a in parallel to this BLUE-white wire as shown below in diagram 1.
- In the same blue harness (#3), find the blue-red wire, but don't cut it. Connect the blue-red wire from the green harness (step b) in parallel to this blue-red wire that you just found. Connect in the same manner as shown in diagram 1.
- Put the insulation tape on the end of blue and blue-red wires that are just hanging in the air now.
- Connect harnesses back. Right above the gray and green harnesses on the GEM, there is a colour diagram that will help you put them back in the proper slots.
Make sure that harnesses are secured back in the slots, and put back the glovebox. The front part is done. Now, the wires (from gray and green harnesses) that go to the tail lights will only have the corresponding turn signal without stop.
Empty the trunk. Push the seats into the passenger area as to make more space for yourself, for you will sit in the trunk while re-wiring the wires.
Remove the plastic left frame that the seatbelt is coming from. You don't have to remove it completely, but loosen it enough to remove the side carpet-like material that covers the entire rear left wall. When you remove it, you will see the following:
Don't change anything below the harnesses. Start from the blue harness and go up until the thick black wire splits apart. One will go to the left tail light, and another - to the right one. Start working on them soon after they become separated. Let's call them the left sleeve and the right sleeve respectively. The left sleeve is relatively short because the left tail light is right up there. The right sleeve will go under the trunk carpet and finally reach the right tail light.
Left (short) sleeve:
- Remove the black insulation 2 cm upward from the point where the wires split. You will see five wires: orange, blue, black, green-black, black.
- Cut the blue wire. Turn on the left signal and with the curcuit tester check if the blue wire is really a left turn signal.
- Cut the green-black wire. Connect the harness end of the blue wire to the tail light end of the green-black wire.
- In step c, you made the left b/u light act as the blinker, but you lost the actual back-up light. The reverse signal is still availabe from the harness end of the green-black wire that is hanging in the air at this moment. It's up to you where to put the new reverse lights.
Right (Long) sleeve:
- Remove the black insulation 2 cm upward from the point where the wires split. You will see five wires: orange, blue-red, black, green-xxx, black (I am not sure what colour xxx is).
- Cut the blue-red wire. Turn on the right signal and with the curcuit tester check if the blue-red wire is really a right turn signal.
- Cut the green-xxx wire. Connect the harness end of the blue-red wire to the tail light end of the green-xxx wire.
- In step c, you made the right b/u light act as the blinker, but you lost the actual back-up light. The reverse signal is still availabe from the bottom end of the green-xxx wire that is hanging in the air at this moment. It's up to you where to put the new reverse lights.
Sharing the stops from the stop mount light:
- Start going up from the gray wider harness. Remove the insulation so that it is near the place where you did re-wiring on the left and right sleeves.
- Find the green-yellow wire. Don't cut it.
- Cut a fairly long stretch of the wire that you purchased at Wal-Mart (Autozone, Cragen, wherever). The wire should be 16 GA. Connect this wire in parallel with the green-yellow wire that you found in step b. From now on, let's call this extra wire a "stop" wire. See diagram 2.
- Run the "stop" wire to the tail light end of the blue wire in the left sleeve. Connect the blue wire in parallel with the "stop" wire. In this step, don't cut the "stop" wire. Now, you connected the left tail light to the stop signal. Ask your friend to step on the brakes. If the mount stop light and the left stop light work good, proceed to the next step.
- Continue running the "stop" wire to the tail light end of the blue-red wire in the right sleeve. Connect the blue-red wire to the "stop" wire. Step on the brakes once again. If all three brake lights function, you are almost done.
Check all your turning signals and observe the former back-up lights. Now, they should act as the blinkers. Check the brake lights once again. Install all frames back, and try to make the car look like it did before
Right now, you don't have the back-up lights. One solution would be to purchase a Euro-bumper with the back-up lights installed. Or, you may install custom clear lights wherever you want. Just don't forget which wire is your reverse signal (the harness end of the green-black wire that is hanging free).
Another link to HOW TO: http://olmikul.home.comcast.net/taillights.htm